Siemens Aktiengesellschaft

Marcel Benecke

Diethard Runggaldier

Peter Kaluza

Josef Burger

Andreas Fritsch

A method is disclosed for operating a synchronous machine via a three-phase power controller including three semiconductor controllers and connected to a three-phase network. The method includes determining the phase difference between the magnet-wheel voltage of the synchronous machine and the network voltage of the three-phase network; determining the rotational speed of the rotor of the synchronous machine; determining the phase position of the three-phase network; determining at least some of the stator currents of the synchronous machine; determining a decision characteristic number based upon an advance calculation of the torque curve in the event of activation of at least two of the semiconductor controllers while taking into account the current values for phase difference, rotational speed, stator current, and phase position; and determining at least one switching time point based upon the decision characteristic number, wherein the at least two semiconductor controllers are activated at the switching time point.

Method and assembly for operating synchronous motors

A method is disclosed for operating a synchronous machine by way of a three-phase AC power controller, which is connected to a three-phase network. The embodiment of the method includes determining the phase difference between the magnet-wheel voltage of the synchronous machine and the network voltage of the three-phase network; determining the rotational speed of the rotor of the synchronous machine; determining the phase position of the three-phase network; determining a decision characteristic number on the basis of a stored data table calculated in advance, which data table associates a decision characteristic number with value triples of phase difference, phase position, and rotational speed; and determining at least one switching time point on the basis of the decision characteristic number.

The synchronous motors are controlled by a three-phase AC power controller. According to an embodiment of the invention, firing points for the AC power controller are determined. A pair of two or three phases is determined from the angular position of the rotor, for which the firing points can be present for the respective A.C power controller. Actual firing points are determined from the mains voltage phase position of the phases so that only positive torque is produced.

Device for operating synchronous motors and associated method

Synchronous motors are controlled using a three-phase AC power controller. According to at least one embodiment of the invention, a fundamental wave having the desired frequency is defined for the first phase, and corresponding fundamental waves which have the same frequency as the frequency in the first phase but are out of phase by specific values are defined in the other phases. The triggering times during which the generated current pulse concurrently has the same polarity as the respective fundamental wave in two of the phases are determined for each phase and are used. Two of the three fundamental waves are generated in phase opposition when the desired frequency amounts to half the system frequency.

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Magdeburg, Germany

Marcel Benecke